Single neuron population studies are being carried out to determine the cellular composition and circuitry at several levels of the somatosensory system of the domestic cat. The cerebral cortex appears to have two major modes of operation, as exemplified by the primary evoked response, augmenting response, callosal response and type I spindles on the one hand, and the generalized secondary response, recruiting response and type II spindles on the other. Single neuron responses and the patterns of net vertical current flow during each of these phenomena are being recorded and analyzed. In order to carry out such studies and handle the massive amount of data involved, a fully automated laboratory capability is being developed. This involves automatic manipulation of the microelectrodes in the tissue, automatic detection and isolation of the signals from single neurons, automatic application of test stimuli to the animal in a dynamically altering way such that a long list of experimental questions is asked of each neuron, but the sequencing of the questions varies according to the pattern of the previous answers. In this manner, a maximum amount of information can be gained under uniform conditions from a minimum number of experimental animals. This requires a large capacity, very fast computing system, capable of receiving input from several electrodes and physiological monitoring devices while simultaneously stimulating the animal, processing the input data and responding to the monitor inputs.